ANTENTOP- 01- 2011, # 015

Cylindrical EH- antenna

for the 20- meter Band

It is not wisely to use RF- Choke on a ferrite ring because the heating the ring when the antenna is transmitting, so, parameters of the antenna would be changed also as well. RF- Choke should be made like several (3-7) turns in 10- 20 cm in diameter coiled by the feeding coaxial cable. The RF Choke is place on the length near 5- meters from the antenna.

Antenna is tuned in to resonance:

Roughly: By choosing length of the coaxial cable from Antenna to the RF- Choke

Fine: By changing parameters of the RF- Choke (quantity of turns, diameter of the Choke).

You may try a phase EH- Antenna. With the antenna placed near the window and with 100-Wtts I made QSOs to distance up to 3000 km.

73! RU4SJ

Communication Point. USSR (end of 1970s- beginning of 1980s)

Photo taken from the Internet

www.antentop.org

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